Pitfalls In Estimating ß-Convergence By Means Of Panel Data: An Empirical Test

This paper aims to test the conjecture advanced in a recent work by Bianchi and Menegatti (2007) that usual !convergence panel regressions may produce biased evidence, due to their inability to distinguish between actual catching-up across countries and decreasing growth rates over time within countries. The test considers different sub-groups in a dataset of 72 countries for the period 1970-2000 and introduces both human capital and proxies for technological differences into the analysis. The results confirm the conjecture that traditional evidence about - convergence may be misleading; they also show that catching-up across countries is weaker than usually claimed and that this process occurred only in some sub-groups of countries.Catching-up, Convergence, Economic Growth, Panel Estimation Techniques.

Training to estimate blood glucose and to form associations with initial hunger

BACKGROUND: The will to eat is a decision associated with conditioned responses and with unconditioned body sensations that reflect changes in metabolic biomarkers. Here, we investigate whether this decision can be delayed until blood glucose is allowed to fall to low levels, when presumably feeding behavior is mostly unconditioned. Following such an eating pattern might avoid some of the metabolic risk factors that are associated with high glycemia. RESULTS: In this 7-week study, patients were trained to estimate their blood glucose at meal times by associating feelings of hunger with glycemic levels determined by standard blood glucose monitors and to eat only when glycemia was < 85 mg/dL. At the end of the 7-week training period, estimated and measured glycemic values were found to be linearly correlated in the trained group (r = 0.82; p = 0.0001) but not in the control (untrained) group (r = 0.10; p = 0.40). Fewer subjects in the trained group were hungry than those in the control group (p = 0.001). The 18 hungry subjects of the trained group had significantly lower glucose levels (80.1 ± 6.3 mg/dL) than the 42 hungry control subjects (89.2 ± 10.2 mg/dL; p = 0.01). Moreover, the trained hungry subjects estimated their glycemia (78.1 ± 6.7 mg/dL; estimation error: 3.2 ± 2.4% of the measured glycemia) more accurately than the control hungry subjects (75.9 ± 9.8 mg/dL; estimation error: 16.7 ± 11.0%; p = 0.0001). Also the estimation error of the entire trained group (4.7 ± 3.6%) was significantly lower than that of the control group (17.1 ± 11.5%; p = 0.0001). A value of glycemia at initial feelings of hunger was provisionally identified as 87 mg/dL. Below this level, estimation showed lower error in both trained (p = 0.04) and control subjects (p = 0.001). CONCLUSION: Subjects could be trained to accurately estimate their blood glucose and to recognize their sensations of initial hunger at low glucose concentrations. These results suggest that it is possible to make a behavioral distinction between unconditioned and conditioned hunger, and to achieve a cognitive will to eat by training

Small Sample Properties of Copula-GARCH Modelling: A Monte Carlo Study

Copula-GARCH models have been recently proposed in the financial literature as a statistical tool to build flexible multivariate distributions. Our extensive simulation studies investigate the small sample properties of these models and examine how misspecification in the marginals may affect the estimation of the dependence function represented by the copula. We show that the use of normal marginals when the true Data Generating Process is leptokurtic or asymmetric, produces negatively biased estimates of the normal copula correlations. A striking result is that these biases reach their highest value when correlations are strongly negative, and viceversa. This result remains unchanged with both positively skewed and negatively skewed data, while no biases are found if the variables are uncorrelated. Besides, the effect of marginals asymmetry on correlations is smaller than that of leptokurtosis. We finally analyse the performance of these models in terms of numerical convergence and positive definiteness of the estimated copula correlation matrix.Copulas, Copula-GARCH models, Maximum Likelihood, Simulation, Small Sample Properties.

A Copula-VAR-X Approach for Industrial Production Modelling and Forecasting

World economies, and especially European ones, have become strongly interconnected in the last decades and a joint modelling is required. We propose here the use of Copulas to build flexible multivariate distributions, since they allow for a rich dependence structure and more flexible marginal distributions that better fit the features of empirical data, such as leptokurtosis. We use our approach to forecast industrial production series in the core EMU countries and we provide evidence that the copula-VAR model outperforms or at worst compares similarly to normal VAR models, keeping the same computational tractability of the latter approach.Forecasting, Industrial Production, Copulas, VAR models.

Pneumomediastinum after transbronchial cryobiopsy

Pneumomediastinum is defined as the presence of air or gas within the mediastinum and it rarely complicates bronchoscopy. We report, to our best knowledge, the first case of pneumomediastinum following a transbronchial cryobiopsy (TBLC). TBLC is considered a safe procedure as compared with both transbronchial biopsy and surgical lung biopsy. Systematic reviews, metanalysis and a Pubmed research, revealed that in literature no pneumomediastinum has been mentioned after TBLC. We report this case for to make it known to interventional pulmonologists the possibility that a pneumomediastinum can follow a TBLC. In our case the spontaneous resolution in few days did not require any intervention

The Global sphere reconstruction (GSR) - Demonstrating an independent implementation of the astrometric core solution for Gaia

Context. The Gaia ESA mission will estimate the astrometric and physical data of more than one billion objects, providing the largest and most precise catalog of absolute astrometry in the history of Astronomy. The core of this process, the so-called global sphere reconstruction, is represented by the reduction of a subset of these objects which will be used to define the celestial reference frame. As the Hipparcos mission showed, and as is inherent to all kinds of absolute measurements, possible errors in the data reduction can hardly be identified from the catalog, thus potentially introducing systematic errors in all derived work. Aims. Following up on the lessons learned from Hipparcos, our aim is thus to develop an independent sphere reconstruction method that contributes to guarantee the quality of the astrometric results without fully reproducing the main processing chain. Methods. Indeed, given the unfeasibility of a complete replica of the data reduction pipeline, an astrometric verification unit (AVU) was instituted by the Gaia Data Processing and Analysis Consortium (DPAC). One of its jobs is to implement and operate an independent global sphere reconstruction (GSR), parallel to the baseline one (AGIS, namely Astrometric Global Iterative Solution) but limited to the primary stars and for validation purposes, to compare the two results, and to report on any significant differences. Results. Tests performed on simulated data show that GSR is able to reproduce at the sub-$\mu$as level the results of the AGIS demonstration run presented in Lindegren et al. (2012). Conclusions. Further development is ongoing to improve on the treatment of real data and on the software modules that compare the AGIS and GSR solutions to identify possible discrepancies above the tolerance level set by the accuracy of the Gaia catalog.Comment: Accepted for publication on Astronomy & Astrophysic

Ambiente e salute a Gela: stato delle conoscenze e prospettive di studio

The high environmental risk area of Gela, Niscemi and Butera includes the Gela Reclamation Site of National Interest (Gela RSNI). If compared to the other sites of national interest, the Gela RSNI is a case in which many important data on environmental matrices and health outcome are available. However these data do not cover all matrices nor the entire risk area, but are mainly limited to the industrial site. These data are also underutilised, almost never integrated, and a clear example of the lacking of coordination and connection between environment and health data collection and management. In Gela there is an important industrial site whose activities have caused over the years a progressive contamination of several environmental matrices, and extremely high levels of chemical toxic, persistent and bio-accumulative pollutants have been found. In this same area, several epidemiological population health studies have been carried out showing a presence of health outcomes higher than in neighbouring areas and in regional data. Most environmental and health data cannot be compared since their respective survey and monitoring systems are planned upon specific regulations having different goals. A local system to assess the relation between environmental pollution and population health is therefore urgently needed to provide risk managers with ad-hoc tools to improve environmental protection and prevent further risks for Gela\u27s population. In this framework, a multidisciplinary working group has been established to study present pollution-exposure-effect data, transform them into a knowledge system, and complete present knowledge on the cycle of pollutants, from migration in the environment to health impact. Workshops were organised in October 2007 and March 2008 in Rome, and in June 2008 in Gela.L\u27area ad alto rischio di crisi ambientale di Gela, Niscemi e Butera include il Sito di Interesse Nazionale per la bonifica di Gela, SIN. A confronto con gli altri, il SIN di Gela ? caratterizzato da ampia disponibilit? di dati di buona qualit? su diverse matrici ambientali e numerosi esiti sanitari. Tuttavia questi dati non coprono tutte le matrici e gli esiti, e sono spesso lacunosi nelle aree esterne al SIN ma interne all\u27area ad alto rischio, che include gli abitati. Inoltre, questi dati sono spesso sottoutilizzati, risulta carente il collegamento tra i due settori ambiente e salute ed un coordinamento organico. Nell\u27area di Gela ? presente un importante polo industriale la cui attivit? ha comportato nel corso degli anni una progressiva contaminazione di diverse matrici ambientali, nelle quali sono stati rilevati livelli estremamente elevati di inquinanti chimici con caratteristiche di tossicit?, persistenza e bioaccumulo. Nella stessa area sono stati effettuati diversi studi epidemiologici sullo stato di salute della popolazione che hanno evidenziato la presenza di patologie in eccesso rispetto alle aree limitrofe e alla regione. La maggior parte dei dati ambientali e sanitari non sono correlabili perch? i sistemi di rilevamento e monitoraggio sono stati pianificati sulla base di normative specifiche con obiettivi differenti. Risulta quindi urgente costruire un sistema locale in grado di valutare l\u27associazione tra l\u27inquinamento ambientale e lo stato di salute della popolazione per poter offrire strumenti mirati ai gestori del rischio per migliorare la protezione ambientale e prevenire ulteriori rischi per la popolazione gelese. In tale contesto, al fine di studiare e sistematizzare le conoscenze attuali sulla concatenazione inquinamento-esposizione-effetto e con l\u27obiettivo di integrare le conoscenze sul ciclo degli inquinanti, dalla migrazione nell\u27ambiente agli effetti sulla salute, ? stato istituto un gruppo di lavoro multidisciplinare per l\u27area di Gela. I seminari si sono svolti a ottobre 2007 e marzo 2008 a Roma e a giugno 2008 a Gela

An electrooptical muscle contraction sensor

An electrooptical sensor for the detection of muscle contraction is described. Infrared light is injected into the muscle, the backscattering is observed, and the contraction is detected by measuring the change, that occurs during muscle contraction, between the light scattered in the direction parallel and perpendicular to the muscle cells. With respect to electromyography and to optical absorption-based sensors, our device has the advantage of lower invasiveness, of lower sensitivity to electromagnetic noise and to movement artifacts, and of being able to distinguish between isometric and isotonic contractions